An example of an article transport facility with travel paths including branching portions and crossing portions is disclosed in JP Publication of Application No. 2013-110370. Each travel rail pair has a left hand side rail positioned on the left hand side and a right hand side rail as seen along the travel direction of an article transport vehicle. The article transport vehicle has mounted members (such as a connecting shaft (12), and a power receiving portion (25), etc.) such that they are positioned between the left hand side rail and the right hand side rail. At a branching portion or a crossing portion, these mounted members need to cross the left hand side rail or the right hand side rail depending on the traveling direction. For example, at a branching portion, a discontinuous section in which the left hand side rail or the right hand side rail is discontinuous exists so that the mounted members do not come into contact with the left hand side rail or the right hand side rail that the mounted members need to cross.
In addition, a crossing portion has movable rails and an actuator device for moving the movable rails. The article transport vehicle includes a pair of right and left travel wheels consisting of a travel wheel that travels on the left hand side rail, and a travel wheel that travels on the right hand side rail. And the movable rails prevent both of the pair of right and left travel wheels of the article transport vehicle from leaving the rails simultaneously in a crossing portion. More specifically, the movable rails are configured to be switched between a position at which one of the movable rails is located in the discontinuous section of the left hand side rail and functions as the left hand side rail and a position at which the other of the movable rails is located in the discontinuous section of the right hand side rail and functions as the right hand side rail. When the article transport vehicle travels through the crossing portion, the positions of the movable rails are changed by means of an actuator device to prevent the mounted members mounted on the article transport vehicle from contacting the left hand side rail and/or the right hand side rail, and to keep both travel wheels from leaving the travel rail pair in the crossing portion. However, with this arrangement, it is necessary to provide the movable rails and the actuator device for moving the movable rails in the crossing portion, leading to a complex structure of the crossing portion.